1. Field of the Invention
The present invention is in the field of fluid-flow couplings which may be generally characterized as of the "mutually-closing, dry break" type. Such couplings are arranged to be interconnected in order to allow a fluid to flow between the couplings (i.e., usually between a pair of hoses or conduits, or between a tank or vessel and a conduit, for example). Upon being disconnected, the couplings mutually reseal so that fluid does not flow to the ambient. Additionally, the residual volume of fluid released to the ambient upon disconnection of the couplings is minimal.
More particularly, the present invention relates to a fluid-flow coupling which includes a complementary first part and second part, which when connected to one another may effect fluid-flow communication. When the coupling parts are connected they may be used to effect fluid-flow communication between a vessel and a conduit, for example. When the coupling parts are disconnected they mutually reseal so that fluid is not lost either from the conduit or from the vessel. Additionally, the "dry break" aspect of these couplings means that each coupling part desirably has a minimal retention volume of fluid, which fluid is not sealed either in the first or second coupling part upon disconnection, and which is thus released into or exposed to ambient conditions.
Further, the present invention relates to such a coupling which additionally has a controllable valve mechanism integrally formed as part of each coupling part, and which allows a user of the coupling parts to connect them while preventing fluid flow communication through the coupling. Alternatively, the user can fully open fluid flow communication through the connected coupling parts, or can regulate this fluid flow to control a flow rate of fluid between a vessel and a conduit, for example.
2. Related Technology
A conventional coupling structure is known in accord with U.S. Pat. No. 4,942,901, (the '901 patent), issued 24 Jun. 1990 to Petro Vescovini. It is believed that this '901 patent discloses a coupling structure having a first coupling and a second coupling which are both generally cylindrical. These couplings axially engage with and disengage from one another. When the couplings are engaged, a poppet valve of each coupling engages the poppet valve of the other to mutually force the poppet valves off their respective seats. The poppet valves are referred to by Vescovini as shutter valves, and each includes a protrusion engaging the protrusion of the other shutter valve to mutually open these shutter valves. When the couplings of the '901 patent are disengaged from one another, the shutter valves are closed by respective springs so that each coupling closes a respective conduit or hose to which it is attached.
Another conventional coupling which is similar in some respects to that disclosed in the Vescovini '901 patent, is set out in U.S. Pat. No. 5,316,041, (the '041 patent), issued 31 May 1994, to Patrick J. Ramacier, et al. The '041 patent is believed to disclose a quick disconnect coupling structure in which a male and female coupling members are axially engageable with and disengageable from one another. When the coupling members are engaged with one another, a poppet valve member of each is unseated and allows fluid flow between the coupling members. When the coupling members are disconnected from one another, each poppet valve member reseats under the bias provided by a respective spring, and the conduits or hoses with which the coupling members are associated are thus closed.
Still another coupling structure is seen in U.S. Pat. No. 4,421,146 (the '146 patent), issued 20 Dec. 1983 to Curtis J. Bond, et al. A coupling structure according to the '146 patent includes a tubular spout attached to and in fluid communication with a fluid-filled vessel, such as a bag held within a cardboard box. This spout portion includes a plug member which is axially moveable between a first position closing fluid communication between the vessel and an outer portion of the spout member, and a second position opening this fluid communication. In the second position of the plug member a pair of lateral openings at an inner portion of the plug member are moved inwardly of the spout to permit fluid communication between the vessel and the outer portion of the spout.
A service member (i.e., the male coupling part) is carried in a guide structure which clamps to the spout and guides the service member for axial sliding engagement into sealing relation with the spout. The service member provides communication with a conduit, and includes a valve member closing communication between the conduit and ambient when the service member is disconnected from the spout. The service member as it engages the spout is also engageable with the plug member to move it between its two positions, and engagement between the service member and plug member opens the valve in the service member. Thus, when the service member is engaged into the spout, communication between the vessel and the conduit is established. Further, it is seen that the plug member of the '146 patent carries an axial projection which contacts the valve member of the service member (the male coupling part), and opens this valve member.
When the service member and spout member of the coupling according to the '146 patent are axially disengaged from one another, a small volume of fluid is retained outwardly of the valve member and spout. This retention volume of fluid is small because the service member defines a domed end surface, and the plug member has a matching contoured end wall closely fitting to the valve member. The lateral ports of the plug member are themselves of small volume, and the passage leading to the plug member is small and is mostly filled by the plug valve member itself when this member is moved to its closed position.
Another conventional coupling, which may be considered to be of hermaphrodite configuration, is known from European patent application No. 0 294 095 A1, published 7 Dec. 1988 (the '095 application). According to the '095 application, a "male" and "female" coupling parts are brought into alignment and juxtaposition by a yoke carried on a guide housing. The male coupling part is configured as a tubular member which is axially movable by a handle on the guide housing to engage with an annular valve member carried in the female coupling part. When the male and female coupling parts are coupled with one another (i.e., by extension of the male coupling part relative to the guide housing and into the female coupling part), an inner liquid extraction flow path is separated from an outer air-entrance (or pressurized gas delivery) flow path by the annular valve member of the female coupling. In the coupled condition of the male and female couplings, the annular valve member of the female coupling part also serves as a sealing member. A version of this coupling is also known in which the male coupling part carries a spring-loaded internal disk valve member which closes the liquid extraction flow path of the male coupling part when the male and female coupling parts are not coupled with one another.